rate_function: This implements an exponential model of the firing-rate-force...

In ime-luebeck/semgsim: Simulating surface electromyographic (sEMG) and force signals

This implements an exponential model of the firing-rate-force relationship relationship, as proposed in "Relationship between firing rate and recruitment threshold of motoneurons in voluntary isometric contractions" [De Luca, Hostage] (2010). The model is

Description

fr_i(x) = Dx + (C - A exp(-x/B)) x_i + E

Usage

rate_function(muscle_load, params)

Details

where fr_i(x) denotes the firing rate of motoneuron i at excitation level x, and x_i denotes the recruitment threshold of that motoneuron. The remaining parameters are constant parameters of the rate coding model that describe the rate coding behavior of a particular muscle.

The model respects the following principles:

• The 'onion-skin' phenomenon: at each point in time, earlier recruited MUs maintain higher firing rates than later recruited ones.

• Firing-rate curves converge to similar (here: the same) firing rates at high force levels.

• At a given value of force, higher-threshold MUs display higher slopes in their firing-rate-force curves.

• Initial firing rates of MUs increase with the recruitment threshold.

ime-luebeck/semgsim documentation built on April 14, 2022, 11:02 p.m.